and who wants to go anywhere on a restricted ticket anyway (unless its someone else's money paying the bill)

I would suspect that 25000 can be met if you are an elite and play your routings and fly 2 times...back in my co days I did it, of course united has that mountain hub in the way and the "boomerang" strategy doesnt work well...in fact all their hubs are in a line but i would suspect that some of the texas-california or southeast-northwest routes have enough pitch in the routings to make it easy...